brent chapman tera corbari matt devers. the views expressed in this presentation are those of the...

Watching the Watcher: The Prevalence of Third-party Web Tracking Brent Chapman

Tera CorbariMatt Devers

Disclaimer

The views expressed in this presentation are those of the authors and do not reflect the official policy or position of the United States Military Academy, the Department of the Army, the Department of Defense or the U.S. Government. 

Introduction

Benefits/LegitimacyPrivacy Concerns

Sample Webpage

1Log

Entry

1Log

Entry

1Log

Entry

1Log

Entry

4 LogEntries

adserver.com

Embedded Content

Primary means of 3rd parties reaching the end user

advertising affiliate networks

the usual suspects (doubleclick, google)

actively encouraged

Every Tag tells a story Objects (Maps,

Flash player, etc.) Images Videos Scripts Style Sheets iFrames

<EMBED>……</EMBED>

http://aruljohn.com/details.php

Technique used to increase effectiveness of advertising campaigns

Group ProfilingHow an advertiser can turn your IP

address into your digital identityYou are no longer anonymous

Behavioral Targeting

“By referring to javascript that’s hosted elsewhere, you’re basically at the mercy of that other organization…to not do evil with it”

-David Campbell, security expert

“If I wanted a backdoor into the website, this would be one of the best ways to do it.”

Urchin.js

AdBlock Plus

2o7.net armytimes.com gcion.com mavenapps.net militarytimes.co

m theplatform.com google-

analytics.com

Packet Level

• 208.79.X.X• 2o7.net• akamai.net• gbahn.net• gcion.com• militarytimes.com• webtrends.akadns.net• www-google-

analytics.l.google.com

ArmyTimes.com

Visit top 25 Alexa sitesUse AdBlock Plus to construct a

dataset of external objects

Dataset available

Analysis Methodology

Alexa Rankings(Top 25 in the United States)

1. Google2. Yahoo3. MySpace4. YouTube5. Facebook6. Windows Live7. MSN8. Ebay9. Wikipedia10. AOL11. Amazon12. Craigslist13. Blogger14. Go15. CNN16. Photobucket17. Microsoft18. ESPN19. Comcast20. Flickr21. Ask22. Weather.com23. IMDB24. WordPress25. New York Times

Most Chatty – AOL

Most Chatty – ESPN

Most Chatty – New York Times

Good Listeners – Doubleclick

Good Listeners – Google

Good Listeners – 2o7, dl-rms, Yahoo

What can we do?

Use available plug-ins and services AdBlock Plus NoScript Tor Privoxy

Explore legal protections Claim with Federal Trade Commission

This talk covered what we can see. What happens out of channel or above the user level?

How can we visualize this better?How can we organize this better?Are there more advanced techniques

out there?

Future Work

Watching the Watcher: The Prevalence of Third-party Web Tracking Brent Chapman

Tera CorbariMatt Devers